Presently, there are several devices available to view a fixed stereo image pair. One well-known device is the "Viewmaster" children's toy, which has a binocular-type front viewing port. The device operates by viewing stereo slides which are mounted on a cardboard circle having an approximate diameter of 68 mm. The two slides are mounted on opposite ends of the cardboard circle. Optics are used to present the proper images of the stereo slide pair to the left and right eye of the viewer. This allows the left eye and right eye slides, i.e., the fixed stereo image pair, to achieve a 3-dimensional (3-D) effect.
Another known type of 3-D viewer allows for the viewing of stereo print images. The stereo prints are placed beneath a binocular viewing tripod, which is located approximately 8-10 inches above the print image plane. By looking through the viewer, the operator sees a 3-D effect. This viewing technique is widely used for military 3-D reconnaissance photography and intelligence gathering.
A flying spot scanner for converting stereo slides to video signals is described in the article "New Aspects and Experiences in Stereoscopic Television" SMPTE Journal, November 1984. This 3-D slide scanner scans the stereo slide using a light beam from a flying spot tube which is focused by dual lenses onto the two images of the stereo slide. The device, however, does not allow for the panning and zooming of the fixed medium stereo image pair.
A system for converting standard 2-dimensional images into television signals uses an electronic image converter developed by Kodak AG Research Labs, Stuttgart, Germany, a U.S. application having been filed on July 6, 1990 and has PCT. No. PCT/EP90/01907.
In this system, a fixed image is illuminated by a light ray from a movable light source. The light beam is reflected by a 45 degree mirror and focused by a lens onto a charge coupled device (CCD) image sensor. The CCD sensor output is processed to allow display on a conventional television display. The system includes a sled and cam structure which allows the image to be zoomed and panned while remaining in focus. However, the system operates only for standard 2-dimensional images.
Therefore, there is a need for a 3-D system which allows for the manipulation, i.e. zooming and panning, of a fixed stereo image pair which maintains the resolution of the image.